Engineers: They can create traps for any invaders spiked walls, laser grid, air locks on the floor and other stuff like that also the more people you have in the engine room the better chance you have to doge enemy attacks, and the ability to flee a battle Ship combat: in the bridge you have this po...

maybe there could be a slime alien that leaves a trail and if any of your crew steps on it that slip and damage themselves. And some type of giant bug alien that when you battle you can detain one and try and convert it into a pet. Also there is a special mission that a alien parasite infects one of...